The present invention relates to a control system for Diesel engines, and more particularly to an intake throttling device adapted to an intake manifold of the Diesel engine for reduction of engine vibration and noises.
In general, the level of vibration and noises in operation of a Diesel engine is higher than that in operation of an engine of the spark ignition type. For this reason, the operator and adjacent people are suffering from unpleasant noises particularly in idling operation of the Diesel engine. Such vibration and noises occur at a high level when the Diesel engine is arrested. For the purpose of decreasing the level of the vibration and noises, it has been proposed to throttle the intake air during idling operation of the engine and to fully throttle the intake air when the engine is arrested. It has, however, been observed that if the intake air is throttled in operation of the engine at a high speed under a high loaded condition, there will occur drop of the engine power and worse of the emission color. If the intake air is fully throttled during the idling operation of the engine, there will occur worse of combustion in the engine, resulting in difficulty of the engine operation. It is, therefore, required to systematically solve the above-described problems in application of an intake throttling device to the intake manifold of the Diesel engine.